If implemented, the move would more than double the combined fuel and road tax costs for owners of some of the most popular family cars, in just six years, according to figures from the Society of Motor Manufacturers and Traders.
The changes could mean a charge as much as £1,800 for Band G cars, which were published in the Environmental Audit Committee's Reducing Carbon Emissions from Transport report and have been promoted by some as an anti-4x4 measure.
The SMMT chose two cars in each of the current road tax bands for the analysis. Researchers took August 2006 as the base and tracked back to 2003; they then analysed the position in 2009, on the assumption that VED changes had been made.
Christopher Macgowan, SMMT chief executive, said: "Our analysis shows that changes to road tax would hit drivers of small and family cars in a tax double-whammy, firstly through fuel costs and secondly road tax. It would add more pain to families struggling with rising energy costs at home and threatens to further dampen consumer spending."
Increase in motoring costs by model - fuel and road tax, 2003 - 2009
|VED band||Model||2003||2006||2009*||Six year increase||Percentage increase|
|B||Nissan Micra 1.5 diesel||£766||£873||£1,181||£415||54.1%|
|B||Vauxhall Corsa 1.0 petrol||£782||£875||£1,211||£429||54.9%|
|C||Ford Focus 1.6 diesel||£821||£963||£1,503||£682||84.3%|
|C||Renault Modus 1.2 petrol||£973||£1,125||£1,718||£745||76.6%|
|D||VW Golf 1.4 petrol||£1,081||£1,254||£2,131||£1050||97.1%|
|D||Toyota Corolla 1.4 petrol||£1,110||£1,288||£2,169||£1059||95.4%|
|E||Vauxhall Zafira 1.9 diesel||£1,088||£1,287||£2,402||£1314||120.8%|
|E||Peugeot 307 1.6 petrol||£1,236||£1,439||£2,606||£1370||110.8%|
|F||Volvo S40 2.4 petrol||£1,412||£1,669||£3,114||£1702||120.5%|
|F||Honda Accord Tourer 2.0 petrol||£1,427||£1,689||£3,133||£1706||119.6%|
|G||BMW 5 Series 2.5 petrol||£1,541||£1,856||£3,579||£2038||132.2%|
|G||SEAT Alhambra 2.0 petrol||£1,588||£1,912||£3,640||£2052||129.2%|
(* 2009 figure assumes introduction of Sustainable Development Commission proposal, quoted in Environmental Audit Committee report, to increase road tax, differentiating each band by £300, rising to £1,800 for G band.)